Electrofishing Surveys to Determine Changes in Fish Community Biomass

Biotactic established twenty-two long term monitoring sites (66 sampling subsections) across the Saugeen River watershed within which annual biomass electrofishing surveys are performed to monitor the change in the fish community as a function of the removal of the Truax dam in Walkerton, Ontario, as part of a fisheries offset and compensation project. Backpack electrofishing is used by trained staff to collect all fish within each site. Each fish is then identified, measured, weighed and safely released. Staff also conduct four yearly capture efficiency studies and use the calibration metrics produced to calculate species and site biomass and production values from the collected data.

Baseline phases of this study were conducted in Summer 2018 and 2019 and the Truax dam was removed in August 2019 after surveys were completed. The first year of post-impact monitoring occurred Summer 2020 with annual monitoring scheduled to continue until 2026. To date 29182 fish from 45 different species have been collected across our permanent monitoring locations.

Find additional details regarding the fisheries offset and compensation project here, the radiotelemetry component of this project here, the redd count survey component here, and the videographic survey component here.

A summary of all project findings to-date can be found here.

backpack electrofishing crew
fish sorting
backpack electrofishing process